1. Technical Field
The present invention relates to a method of cleaning air for purifying air by removing chemical pollutants in the air by washing the air with water and to a device used for the method. More particularly, the present invention relates to a method of cleaning air for purifying air to be supplied to a clean room in facilities for manufacturing semiconductors and liquid crystal devices, pharmaceutical factories, life science-related facilities, and the like and to the air cleaning device used for the method.
2. Background Art
In addition to particulate pollutants that have conventionally been the main target for air purification in facilities for manufacturing semiconductors and liquid crystal devices, pharmaceutical factories, life science-related facilities, and the like, elimination of gaseous chemical pollutants has been desired to improve the product yield and product quality. Such chemical pollutants include inorganic metal element such as sodium, potassium, calcium, and boron, anions such as fluorine ion, chloride ion, nitric acid ion, nitrous acid ion, sulfuric acid ion, sulfurous acid ion, and cations such as ammonium ion. Although conventional particulate pollutants can be removed using a dust filter such as a ULPA filter, these chemical pollutants cannot be removed using the ULPA filter.
For this reason, chemical pollutants in the air have conventionally been removed by a method utilizing shower of water drops called water shower or a method of using a chemical filter that can remove chemical components by adsorption. In the method of using the water shower, chemical pollutants are removed by spraying water to the air containing the chemical pollutants.
However, the method of using water shower exhibits only a low efficiency of chemical pollutant removal due to a poor contact efficiency of the air to be processed and water. For this reason, a humidifying means including a water shower device requires a length as large as several meters. In addition to the large space required for the facility, a large pressure loss has been a problem. Expensive deionized water used as shower water is another problem in the water shower method. A large amount of water increases the cost. Recycling deionized water which is a customarily employed way of processing for reducing cost results in a problem of releasing and redistributing once-adsorbed chemical pollutants. The method of using the chemical filter has also a problem of high cost due to the need for an expensive chemical filter which has a limited life of adsorption capability.
Accordingly, an object of the present invention is to provide an air processing method that can remove chemical pollutants in the air with high efficiency and a low cost. Another object of the present invention is to provide an air processing device that is compact, exhibits a reduced pressure loss, and is inexpensive.